Fig. 2: Dynamics and actuation performance of a magnetic soft robot.
a Experimental and simulated snapshots present one actuation period of a one-arm triangle-shaped robot driven by a square wave magnetic field (4 mT, 60 Hz, shown in the inset or the form as Supplementary Fig. 2b) (Supplementary Movie 4). One end of the robot is fixed on a substrate. b Experimental snapshot revealing 90° deformation of a two-arm rectangle-shaped robot (lateral dimensions: 6 × 0.8 mm2, thickness: 45 µm) at a driving frequency of 100 Hz when the amplitude of the magnetic field is 9 mT (square wave). See also Supplementary Fig. 8 and Supplementary Movie 5. The middle point of the robot is fixed on a curved substrate. c Direction of magnetization M and magnetic torque m of a one-arm triangle-shaped robot during actuation as shown in (a). d, e Time-dependent rotation angle during the actuation of a one-arm trapezoid-shaped robot driven by a square wave magnetic field (2 mT) at 20 and 50 Hz, respectively. Maximum rotation angles are highlighted with Greek letters: α is the maximum rotation angle achieved at 20 Hz, β at 50 Hz for one period, and γ at 50 Hz for two periods. The purple lines indicate the trend of the variation of the angle. f, g Calculated frequency-dependent maximum rotation angles of differently shaped robots for one and two periods driven by a square wave magnetic field (2 mT), respectively. Scale bars, 0.2 cm.
